U.S. Pat. No. 2,525,365 issued to W. W. Meyer on Oct. 10, 1950 shows and describes a face seal for sealing the joint between a stationary housing and a rotary shaft. The present invention is directed to a seal of this general type. The principle object of this invention is to provide a face seal that includes a zero rate spring means as the biasing device for maintaining pressure engagement between the sealed faces. This type of spring means is advantageous in that it provides a constant biasing force on the associated sealing disc. Therefore, initial performance is not critically dependent on exact positionment of one disc relative to the other; the constant force spring automatically takes up any lost space that would otherwise occur by reason of improperly located discs. This type of spring means also is advantageous in that it maintains a given biasing force over the entire service life of the seal irrespective of wear that would otherwise change the positions of the sealing disc and thus decrease the effective spring force; with my proposed arrangement the spring force remains constant so that the sealing discs do not have to be overpressurized initially to compensate for loss of spring pressure due to wear.
The invention described herein may be manufactured, used, and licensed by or for the Government for governmental purposes without payment to me of any royalty thereon.